The ESB (Environmental Sensor Box) is a monitoring device that allows you to remotely monitor the temperature, humidity. PLANET Switched IP Power Manager (IPM) is equipped with a console port for connecting to an environmental sensor box (ESB). Temperature and humidity sensors may be added to control the power switch by monitoring the environmental changes. When the temperature and humidity reach the customizable minimum/maximum thresholds set, you will be notified via SMS and e-mail.